Internet Security Introduction

ITU/APNIC/MICT IPv6 Security Workshop

23rd – 27th May 2016 Bangkok

1 Last updated 5th May 2015

Introduction to Internet Infrastructure Security

p  Introduction to the main network security issues that infrastructure operators need to be aware of.

p  This includes discussion on packet flooding, Internet worms, DDOS attacks and Botnets

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Why Security Why do we need security on the

Internet?

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Why Security? p  The Internet was initially designed for

connectivity n  Trust is assumed, no security n  Security protocols added on top of the TCP/IP

p  Fundamental aspects of information must be protected n  Confidential data n  Employee information n  Business models n  Protect identity and resources

p  The Internet has become fundamental to our daily activities (business, work, and personal)

Internet Evolution

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p Different ways to handle security as the Internet evolves

LAN connectivity Application-specific More online content

Application/data hosted in the “cloud”

ACRONYM/TERM OVERLOAD p C I A

n  Confidentiality n  Integrity n  Availability

p Access Control n  Authentication n  Authorisation n  Accountability

p Risk p  Threat p Vulnerability p  Impact

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Goals of Information Security

Confidentiality Integrity Availability

SEC

UR

ITY

prevents unauthorized use or disclosure of information

safeguards the accuracy and completeness of information

authorized users have reliable and timely access to information

Access Control p  The ability to permit or deny the use of an

object by a subject.

p  It provides 3 essential services: n  Authentication (identification of a user) n  Authorisation (who is allowed to use a service) n  Accountability (what did a user do)

Authentication p  a means to verify or prove a user’s identity p  The term “user” may refer to:

n  Person n  Application or process n  Machine or device

p  Identification comes before authentication n  Provide username to establish user’s identity

p  To prove identity, a user must present either of the following: n  What you know (passwords, passphrase, PIN) n  What you have (token, smart cards, passcodes, RFID) n  Who you are (biometrics such as fingerprints and iris

scan, signature or voice)

Authentication – Examples of Tokens

eToken RFID cards

Smart Cards

Fingerprint scanner

Authentication - Trusted Network p Standard defensive-oriented technologies

n  Firewall – first line of defense n  Intrusion Detection – second line of defense

p Build TRUST on top of the TCP/IP infrastructure n  Strong authentication

p  Two-factor authentication p  something you have + something you know

n  Public Key Infrastructure (PKI)

Strong Authentication p  An absolute requirement p  Two-factor authentication

n  Passwords (something you know) n  Tokens (something you have)

p  Examples: n  Passwords n  Tokens n  Tickets n  Restricted access n  PINs n  Biometrics n  Certificates

Two-factor Authentication p  Requires a user to provide at least two

authentication ‘factors’ to prove his identity n  something you know

p  Username/userID and password

n  something you have p  Token using a one-time password (OTP)

p  The OTP is generated using a small electronic device in physical possession of the user n  Different OTP generated each time and expires after

some time n  An alternative way is through applications installed on

your mobile device p  Multi-factor authentication is also common

Authorisation p  Defines the user’s rights and permissions on a

system p  Typically done after user has been authenticated p  Grants a user access to a particular resource and

what actions he is permitted to perform on that resource

p  Access criteria based on the level of trust: n  Roles n  Groups n  Location n  Time n  Transaction type

Authentication vs. Authorisation

Client

Service

Authentication Mechanism Authorisation

Mechanism

“Authentication simply identifies a party, Authorisation defines whether they can perform certain action” – RFC 3552

Authorisation Concepts p  Authorisation Creep

n  When users may possess unnecessarily high access privileges within an organization

p  Default to Zero n  Start with zero access and build on top of that

p  Need to Know Principle n  Least privilege; give access only to information that the

user absolutely need p  Access Control Lists

n  List of users allowed to perform particular access to an object (read, write, execute, modify)

Authorisation - Single Sign On p  Property of access control where a user logs in

only once and gains access to all authorized resources within a system.

p  Benefits: n  Ease of use n  Reduces logon cycle (time spent re-entering passwords

for the same identity) p  Common SSO technologies:

n  Kerberos, RADIUS n  Smart card based n  OTP Token n  Shibboleth / SAML n  OpenID

p  Disadvantage: Single point of attack

Authorisation – Types of Access Control p Centralized Access Control

n  Radius n  TACACS+ n  Diameter

p Decentralized Access Control n  Control of access by people who are closer to

the resources n  No method for consistent control

Accountability p  The security goal that generates the

requirement for actions of an entity to be traced uniquely to that entity n  Senders cannot deny sending information n  Receivers cannot deny receiving it n  Users cannot deny performing a certain action

p Supports nonrepudiation, deterrence, fault isolation, intrusion detection and prevention and after-action recovery and legal action

Source: NIST Risk Management Guide for Information Technology Systems

Integrity p Security goal that generates the

requirement for protection against either intentional or accidental attempts to violate data integrity

p Data integrity n  The property that data has when it has not

been altered in an unauthorized manner p System integrity

n  The quality that a system has when it performs its intended function in an unimpaired manner, free from unauthorized manipulation

Source: NIST Risk Management Guide for Information Technology Systems

Risk, Threats, and Vulnerability p  Threat

n  Any circumstance or event with the potential to cause harm to a networked system

p Vulnerability n  A weakness in security procedures, network

design, or implementation that can be exploited to violate a corporate security policy

p Risk n  The possibility that a particular vulnerability

will be exploited

Threat p  “a motivated, capable adversary” p  Examples:

n  Human Threats p  Intentional or unintentional p  Malicious or benign

n  Natural Threats p  Earthquakes, tornadoes, floods, landslides

n  Environmental Threats p  Long-term power failure, pollution, liquid leakage

Vulnerability p A weakness in security procedures,

network design, or implementation that can be exploited to violate a corporate security policy n  Software bugs n  Configuration mistakes n  Network design flaw n  Lack of encryption

p Where to check for vulnerabilities? p  Exploit

n  Taking advantage of a vulnerability

Risk p  Likelihood that a vulnerability will be exploited p  Some questions:

n  How likely is it to happen? n  What is the level of risk if we decide to do nothing? n  Will it result in data loss? n  What is the impact on the reputation of the company?

p  Categories: n  High, medium or low risk

Risk = Threat * Vulnerability * Impact

What Can Intruders Do? p  Eavesdrop - compromise routers, links, or

DNS p Send arbitrary messages (spoof IP

headers and options) p Replay recorded messages p Modify messages in transit p Write malicious code and trick people into

running it p  Exploit bugs in software to ‘take over’

machines and use them as a base for future attacks

What are Security Goals? p Controlling Data Access p Controlling Network Access p  Protecting Information in Transit p  Ensuring Network Availability p  Preventing Intrusions p Responding To Incidences

Goals are Determined by p Services offered vs. security provided

n  Each service offers its own security risk p  Ease of use vs. security

n  Easiest system to use allows access to any user without password

p Cost of security vs. risk of loss n  Cost to maintain

Goals must be communicated to all users, staff, managers, through a set of security rules called “security policy”

Causes of Security Related Issues

p  Protocol error n  No one gets it right the first time

p  Software bugs n  Is it a bug or feature ?

p  Active attack n  Target control/management plane n  Target data plane n  More probable than you think !

p  Configuration mistakes n  Most common form of problem

Why Worry About Security? p How much you worry depends on risk

assessment analysis n  Risk analysis: the process of identifying

security risks, determining their impact, and identifying areas requiring protection

p Must compare need to protect asset with implementation costs

p Define an effective security policy with incident handling procedures

Characteristics of a Good Policy p Can it be implemented technically? p Are you able to implement it

organizationally? p Can you enforce it with security tools and/

or sanctions? p Does it clearly define areas of

responsibility for the users, administrators, and management?

p  Is it flexible and adaptable to changing environments?

RFC2916-h+p://www.ie3.org/rfc/rfc2196.txt

What Are You Protecting? p  Identify Critical Assets

n  Hardware, software, data, people, documentation

p  Place a Value on the Asset n  Intangible asset – importance or criticality n  Tangible asset – replacement value, training

costs and/or immediate impact of the loss p Determine Likelihood of Security Breaches

n  What are threats and vulnerabilities ?

Impact and Consequences p Data compromise

n  Stolen data n  can be catastrophic for a financial institution

p  Loss of data integrity n  Negative press or loss or reputation (bank,

public trust) p Unavailability of resources

n  The average amount of downtime following a DDoS attack is 54 minutes

n  The average cost of one minute of downtime due to DDoS attack is $22,000*

*BasedonaPonemonInsDtutestudy(2012)

Risk Mitigation vs Cost Riskmi'ga'on:theprocessofselecDngappropriatecontrolstoreducerisktoanacceptablelevel.ThelevelofacceptableriskisdeterminedbycomparingtheriskofsecurityholeexposuretothecostofimplemenDngandenforcingthesecuritypolicy.Assessthecostofcertainlossesanddonotspendmoretoprotectsomethingthanitisactuallyworth.

Will I Go Bankrupt ?

Is it an embarrassment ?

Evolution of Attack Landscape email propagation of malicious code

“stealth”/advanced scanning techniques

widespread attacks using NNTP to distribute attack

widespread attacks on DNS infrastructure

executable code attacks (against browsers)

automated widespread attacks

GUI intruder tools

hijacking sessions

Internet social engineering attacks

packet spoofing automated probes/scans

widespread denial-of-service

attacks

techniques to analyze code for vulnerabilities

without source code

DDoS attacks

increase in worms

sophisticated command & control

anti-forensic techniques

home users targeted

distributed attack tools

increase in wide-scale Trojan horse distribution

Windows-based remote controllable

Trojans (Back Orifice)

Intruder Knowledge

Atta

ck S

ophi

stic

atio

n

1990 2012

Attack Motivation p Criminal

n  Criminal who use critical infrastructure as a tools to commit crime

n  Their motivation is money p War Fighting/Espionage/Terrorist

n  What most people think of when talking about threats to critical infrastructure

p  Patriotic/Principle n  Large groups of people motivated by cause -

be it national pride or a passion aka Anonymous

Attack Motivation p Nation States want SECRETS p Organized criminals want MONEY p  Protesters or activists want ATTENTION p Hackers and researchers want

KNOWLEDGE

Source:NANOG60keynotepresentaDonbyJeffMoss,Feb2014

The Threat Matrix

Degree of Focus

Opportunistic hacks

Joy hacks Targeted attacks

Advanced Persistent

Threats

Attack Sources p  Active attack involves writing data to the network.

It is common to disguise one’s address and conceal the identity of the traffic sender.

p  Passive attack involves only reading data on the network. Its purpose is breach of confidentiality.

Active Attacks Passive Attacks Denial of Service attacks Spoofing Man in the Middle ARP poisoning Smurf attacks Buffer overflow SQL Injection

Reconnaissance Eavesdropping Port scanning

Source: RFC 4778

Attack Sources p  On-path vs. Off-path

n  On-path hosts can read, modify, or remove any datagram transmitted along the path

n  Off-path hosts can transmit datagrams that appear to come from any hosts but cannot necessarily receive datagrams intended for other hosts

p  Insider vs. outsider n  What is definition of perimeter/border?

p  Deliberate vs. unintentional event n  Configuration errors and software bugs are as harmful

as a deliberate malicious network attack

Source: RFC 4778

General Threats p  Masquerade

n  An entity claims to be another entity p  Eavesdropping

n  An entity reads information it is not intended to read p  Authorisation violation

n  An entity uses a service or resource it is not intended to use p  Loss or modification of information

n  Data is being altered or destroyed p  Denial of communication acts (repudiation)

n  An entity falsely denies its participation in a communication act p  Forgery of information

n  An entity creates new information in the name of another entity p  Sabotage

n  Any action that aims to reduce the availability and/or correct functioning of services or systems

Reconnaissance Attack p  Unauthorised users to gather information about

the network or system before launching other more serious types of attacks

p  Also called eavesdropping p  Information gained from this attack is used in

subsequent attacks (DoS or DDoS type) p  Examples of relevant information:

n  Names, email address p  Common practice to use a person’s first initial and last

name for accounts n  Practically anything

Man-in-the-Middle Attack p Active eavesdropping p Attacker makes independent connections

with victims and relays messages between them, making them believe that they are talking directly to each other over a private connection, when in fact the entire conversation is controlled by the attacker

p Usually a result of lack of end-to-end authentication

p Masquerading - an entity claims to be another entity

Session Hijacking p  Exploitation of a valid computer session, to gain

unauthorized access to information or services in a computer system.

p  Theft of a “magic cookie” used to authenticate a user to a remote server (for web developers)

p  Four methods: n  Session fixation – attacker sets a user’s session id to

one known to him, for example by sending the user an email with a link that contains a particular session id.

n  Session sidejacking – attacker uses packet sniffing to read network traffic between two parties to steal the session cookie.

Denial of Service (DoS) Attack p  Attempt to make a machine or network resource

unavailable to its intended users. p  Purpose is to temporarily or indefinitely interrupt

or suspend services of a host connected to the Internet

p  Saturating the target with external communications requests (server overload) n  May include malware to max out target resources,

trigger errors, or crash the operating system p  DDoS attacks are more dynamic and comes from

a broader range of attackers p  Can be used as a redirection and reconnaissance

technique

Reflected Denial of Service (rDoS) p  Involves sending forged requests to

hundreds of machines with replies directed to a victim server

p Attacker modifies the source IP address (spoofing)

p Replies are expected to be much bigger than the request

p DNS is used for this due to its lack of source validation

Summary - Most Common Threats and Attacks p  Unauthorized access – insecure hosts, cracking p  Eavesdropping a transmission – access to the

medium n  Looking for passwords, credit card numbers, or business

secrets p  Hijacking, or taking over a communication

n  Inspect and modify any data being transmitted p  IP spoofing, or faking network addresses

n  Impersonate to fool access control mechanisms n  Redirect connections to a fake server

p  DOS attacks n  Interruption of service due to system destruction or

using up all available system resources for the service n  CPU, memory, bandwidth

Attack Trends p  Key findings:

n  Largest DDoS attack at 309Gbps n  Multiple attacks over 100Gbps n  Hacktivism is top commonly perceived motivation behind

attacks n  Customers are the most common target of attacks, with

service infrastructure coming second

Source:ArborNetworksWorldwideInfrastructureSecurityReport2014

Attack Trends p  Infrastructure-based attacks were the preferred

attack vector (more than 80% of DDoS attacks) n  SYN floods, UDP floods, DNS, ICMP, ACK floods,

CHARGEN, SNMP

Source: Prolexic Q2 2014 Global DDOS Attack Report

Attack Trends p Downward trend in the use of application-

layer attacks p  “To launch significant DDoS layer 7 attack

campaigns, attackers need to possess sophisticated skills. Few attackers are capable of these attacks, as it requires compromising servers and applications by the exploitation of vulnerabilities, and often requires code customization”

Source:ProlexicQ22014GlobalDDOSA+ackReport

Attack Trends - Breach Sources

Infiltration

Aggregation

Exfiltration

Source:Trustwave2012GlobalSecurityReport

Global Map of DDoS Attacks

https://www.stateoftheinternet.com/trends-visualizations-security-real-time-global-ddos-attack-sources-types-and-targets.html

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Internet Security Introduction

ITU/APNIC/MICT IPv6 Security Workshop

23rd – 27th May 2016 Bangkok

53 Last updated 5th May 2015